The present invention relates to an appearance inspection in a pre-process for a semiconductor wafer, and, more particularly, to a semiconductor device defect inspection method and its system for inspecting points specified in advance and efficiently evaluating the situation of the defect occurrence.
Along with miniaturization of the circuit patterns of the semiconductor devices, the accuracy of the manufacturing method thereof has been increased. With this circumstance, a change is recognized also in defects to occur. That is, conventionally, dominant defects have been those defects which randomly occur due to dust, foreign substances, and the like. On the contrary, increasing defects are those defects which have a high design dependency correlating with alignment of the wiring or elements, or which occur due to the form of a particular layer (also called a layer) or the overlapping of layers. Those defects having a high dependency of circuit design are called “systematic defects”. For example, the defects include a short of the transcription pattern and disconnection due to an optical proximity effect in an exposure process, a resistance anomaly, and a contact hole conduction failure. The resistance anomaly is caused by a change in the pattern form due to a difference in the base. The conduction failure is caused by insufficient etching of a gate oxide film in a particular area.
The circuit design has been made, not to cause occurrence of the systematic defects. However, some parts with less process margin remain as hot spots (positions in which defects are likely to occur due to a change in the process). The hot spot include not only a point which can be foreseen before manufacture through simulation, but also a point which is set as knowledge accumulated experimentally after manufacture. The systematic defects occurring at these hot spot may be prevented in many cases, by changing a part of manufacturing conditions. There is much demand on a function for determining the existence of defects occurred at hot spots, based on defects detected by the inspection device.
As a method for observing the systematic defects, Patent literature 1 discloses a method. In this method, an inspection image corresponding to a defect part and acquired through the appearance inspection is compared with imaged design data, and the circuit parts on the corresponding design data are specified and classified by circuit shape, thereby detecting the circuit shape which appears with high frequency.
Patent literature 2 suggests determining hot spots by matching the geometrical features of defects detected by an appearance inspection device with design data.